To date, 12 breast cancer predisposition genes including ATM, BARD1, BRCA1, BRCA2, CDH1, CHEK2, NF1, PALB2, PTEN, RAD51C, RAD51D, and TP53 have been identified (Tischkowitz et al., 2012; Antoniou et al., 2014; Easton et al., 2015; Couch et al., 2017; Palmer et al., 2020). This evidence concerns the gene BRCA2 and breast cancer.